# smp? ( exactly-one-of ( kaapi tbb ) )
sci-libs/vtk tbb

# exactly-one-of ( expat xml )
media-libs/libmetalink expat

# exactly-one-of ( python_single_target_python2_7 python_single_target_python3_4 python_single_target_python3_5 python_single_target_python3_6 )
kde-apps/lokalize -python_single_target_python2_7

# exactly-one-of ( mysql postgres )
net-dns/mydns postgres

# exactly-one-of ( agent hybrid local server ) at-most-one-of ( mysql postgres )
net-analyzer/ossec-hids hybrid postgres

# exactly-one-of ( iptables nftables )
net-misc/connman -nftables

# exactly-one-of ( gbm raspberry-pi wayland X ) ( gbm wayland X ) vdpau? ( !gbm )
media-tv/kodi -gbm -wayland

# jit? ( lua_single_target_luajit )
# exactly-one-of ( lua_single_target_luajit lua_single_target_lua5-1 lua_single_target_lua5-2 lua_single_target_lua5-3 )
mail-filter/rspamd lua_single_target_luajit -lua_single_target_lua5-1

# lua? ( exactly-one-of ( lua_single_target_lua5-2 lua_single_target_lua5-3 ) )
#app-editors/vis lua_single_target_lua5-3

# exactly-one-of ( lua_single_target_lua5-2 lua_single_target_lua5-3 )
#app-admin/lsyncd lua_single_target_lua5-3

# exactly-one-of ( mariadb mysql )
dev-ruby/mysql2 mariadb

# exactly-one-of ( bliss nauty )
sci-mathematics/polymake nauty

# exactly-one-of ( apache2-server nginx )
www-apps/icingaweb2 nginx

# exactly-one-of ( git gitea gitolite )
acct-user/git gitea

# exactly-one-of ( lua_single_target_luajit lua_single_target_lua5-3 lua_single_target_lua5-4 )
dev-lang/fennel lua_single_target_lua5-4

# exactly-one-of ( apulse pulseaudio )
net-im/viber -apulse